Thermoformed packaging such as blister packs and clamshells typically end up in landfills, even though many of are made of PC PET, the usually recycled material that is blow molded into soft drink and water bottles. That’s a problem for manufacturers concerned about sustainability and product packaging. And the economics of recycling will probably prevent widespread recycling of thermoform-grade RPET for some time. (The “R” of RPET means the polymer comprises virgin material plus regrind, or recycled content.)

In a pilot study conducted by thermoform-packaging maker Dordan Manufacturing in Woodstock, Ill., the company shipped 50 of its RPET clamshells to a local recycling facility to determine how well the containers could be sorted. The waste-management facility uses optics to sort different kinds of polymers.

“The equipment could not distinguish the difference between PET bottles and RPET thermoforms,” says Dordan Manufacturing’s Sustainability Coordinator Chandler Slavin. Theoretically, the two could be recycled together, but that depends on a lot of factors, many of which are a result of the sorting equipment used. In manual sorting, there are problems because clamshells and blisters come in all shapes, sizes, and materials, making it difficult to train workers to sort packages by material type via visual cues in package design. Most clear, thin-neck screw-top beverage bottles are PET, for example, making it easy to identify this recyclable from those destined for landfills, says Slavin.

Another issue: Industry experts suggest there may be fluctuations between the intrinsic viscosity (IV) of PET and RPET that would make them difficult to recycle together. The IV of a material, measured in deciliters per gram, depends on the length of its polymer chains. The longer the chains, the higher the viscosity. Also, RPETs can comprise different ratios of PET, regrind, or recycled polymers. This is one reason why the National Association for PET Container Resources concluded it would be easiest to just recycle PET thermoforms together and keep them out of the PET-bottle-recovery system.

Recycling of thermoforms is an evolving situation, says Slavin. Consequently, there are no standard practices; all collection, sorting, and reprocessing depend on the end market of the material recycled, which differ from region to region. And information about recycling specific materials often gets handed down like folklore among thermoform manufacturers and other interested parties.

“Waste management is a large, complicated, and mature industry that is slow to adopt technologies and processes due to inconsistencies inherent in North American recycling behaviors and established patterns of material recovery,” she says. “For example, a package or material type will not be collected for recycling if there is no buyer,” says Slavin. “And there will be no buyer if there is not a consistent quantity and quality available for reprocessing. Moreover, lots of postconsumer plastics collected for recycling get sold to China where the cost to manually sort it is less than the cost of manually sorting it in the U. S. This reduces the available recycling stream in North America, making the amounts necessary to sustain recycling difficult to quantify.”

In addition, a community’s ability to recycle a package with limited recyclability, like RPET thermoformed containers, can be dictated by whether facilities are private or publicly owned, says Slavin. “Private facilities tend to be better run and maintained than municipally funded ones,” she says. “They also tend to be more economically sustainable. And they use more-sophisticated technologies for sorting and reprocessing. Other factors include the geographical location of the facility (East versus Midwest versus West), which determines what types of materials are collected for recycling and technologies used, based on the available end markets.”

And consider the collection scheme, says Slavin. “How materials are collected for recycling — curbside, drop off, single stream, or commingled — determines how materials comes to recycling facilities,” she says. “This also affects how and what materials are collected for recycling and what sorting schemes are used.” Complicating matters further, buyers’ specs, or the specifications a buyer outlines to suppliers of PC plastics upon procurement, require the material be of a specific material type, such as PET, and packaging type, such as thin-neck screw-top PET beverage containers. For instance, most PET buyers say they do not want bales with RPET thermoforms included for fear of contamination. This discourages MRF’s from investing in sorting technologies that could pull out RPET thermoforms from a batch of look-alike contaminates like PVC.

“The Sustainable Packaging Coalition (SPC) developed the Labeling for Recovery Project to educate consumers on what types of packaging are recycled via a simple labeling scheme. Under the scheme, the label lists components of the packaging and material it is made from. It is intended to tell consumers what can and can’t be recycled rather than what is assumed to be recyclable,” says Slavin. “The hope was to have consumers understand recycling based on the realities of the current system, thereby establishing a demand for increased material recycling. But in developing the initiative, the project team ran into obstacles regarding data applicability. Difficulties arose such as how to determine the types of packaging recycled and the quantity recycled in different geographical regions; whether a community has access to a facility that can recycle the packaging; and whether collection, end markets, and automated sorting are available.

Industry figures suggest that 30 to 59% of American communities can recycle PET thermoforms, which falls within the “limited recyclability” category as per the FTC Green Guides’ definition. “This is changing, however, as industry begins to take a more proactive approach to recycling packaging,” says Slavin. “I foresee the management of recyclables as shifting from publicly to privately owned systems, due in part to the success of such approaches overseas.”

Mail-in your waste The goal at TerraCycle Inc., Trenton, N. J., is to eliminate the idea of waste. It does this by creating national recycling streams for previously nonrecyclable or hard-to-recycle waste. Anyone can sign up for these programs and start sending the company waste. The company converts this into a wide variety of products and materials. According to the company, it has 20 million people collecting waste in over 20 countries and has used them to create over 1,500 different products available at major retailers ranging from Walmart to Whole Foods Market.

How recycling works When a clear PET bottle goes into a curbside bin, the bottle is often picked up by the same truck carrying waste destined for a landfill. Usually the landfill and recovery facility are geographically close to one another, so recyclables are dropped at the recycling facility and waste at the landfill. (Transportation is one of the more-costly considerations in waste management.)

Once at the reprocessing facility, recyclables are “dumped” on the plant floor where a variety of conveyer belts spread the materials along the line for easier identification. Paper is usually sorted first, falling through slits in a tumbler due to weight and dimensions. Plastics are sorted manually or automatically, depended on the facility. In manual systems, workers on the line visually identify materials of a specific type, i.e., HDPE milk jugs. They remove the jugs and place them in separate containers that go to another sorting scheme in the facility or are baled for transportation to an intermediate reprocessor. One popular automated sorting technology uses optics to separate PET from PVC and other undesirables. Aluminum is sorted from other recyclables, and glass is sorted through a weight-based scheme. Sometimes, the municipally contracted hauler or reprocessor separates materials by feedstock type (i.e., paper, plastic, and glass) and then sells the materials to an intermediate plastics or paper reprocessor. It is often privately owned and employs more-sophisticated sorting techniques based on the requirements of the end market.